多变量煤质特性对循环流化床锅炉效率的影响
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摘要
循环流化床燃烧技术是一种比较成熟的洁净煤技术,具有煤种适应性广、燃烧效率高、高效炉内脱硫脱氮及负荷变化范围大等优点,在我国洁净煤发电领域处于优先地位。在目前煤炭市场紧张的形势下,一些燃煤电厂为降低成本、提升自身经济效益,不得不掺烧燃用偏离设计值较多的劣质煤,导致全厂热效率下降,煤耗增加,运行经济性下降。为了研究煤质发生变化时其对锅炉效率的影响,通过锅炉热平衡计算方法,建立多变量煤质特性变化的数学模型,研究煤质特性对锅炉各项热损失的综合影响,获得相应的定量关系。以某超临界循环流化床锅炉燃用不同煤种的燃烧试验为依据,验证了模型的准确性。并以此为基础,探讨了燃用燃料变更为一种矸石、煤泥和末原煤的混煤(BC煤)后锅炉效率的变化。结果表明:随着煤质特性变差,锅炉各项损失增加,变化幅度各不相同,锅炉效率降低。模型计算结果能够为电厂锅炉设计及劣质燃料(矸石、煤泥等)的掺烧提供一定的理论支撑。
Circulating fluidized bed combustion is an advanced and widely used clean coal technology, with fuel flexibility, high combustion efficiency and low emissions etc. In order to lower the fuel cost of the power plant regarding current situation of coal market, low-grade coal is commonly adopted as the blending fuel, which deviates from the designed coal characteristics. However, variations of coal quality result in lower boiler efficiency and higher coal consumption. In the present study, a mathematic model is presented based on the heat balance calculation of the boiler, to investigate the effects of the coal characteristics with multivariable parameters on the heat losses quantitatively. The accuracy of the model is verified by the test results with various coal types in a supercritical CFB boiler. Further research and estimation on the boiler efficiency with a blend fuel(BC coal) consisting of coal gangue, coal slime, etc. is carried out. The results show that the principal heat losses increase and the boiler efficioncy decreases with lower coal quality, providing the fundamental and theoretical support for the boiler design and the blending of low-grade fuel, especially for coal gangue and coal slime.
Circulating fluidized bed combustion is an advanced and widely used clean coal technology, with fuel flexibility, high combustion efficiency and low emissions etc. In order to lower the fuel cost of the power plant regarding current situation of coal market, low-grade coal is commonly adopted as the blending fuel, which deviates from the designed coal characteristics. However, variations of coal quality result in lower boiler efficiency and higher coal consumption. In the present study, a mathematic model is presented based on the heat balance calculation of the boiler, to investigate the effects of the coal characteristics with multivariable parameters on the heat losses quantitatively. The accuracy of the model is verified by the test results with various coal types in a supercritical CFB boiler. Further research and estimation on the boiler efficiency with a blend fuel(BC coal) consisting of coal gangue, coal slime, etc. is carried out. The results show that the principal heat losses increase and the boiler efficioncy decreases with lower coal quality, providing the fundamental and theoretical support for the boiler design and the blending of low-grade fuel, especially for coal gangue and coal slime.
引文
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[13]马栋梁,闫顺林,李永华,等.煤质变化对排烟热损失影响的计算与分析[J].锅炉技术,2008,39(1):47-50.
[14]宋畅,吕俊复,杨海瑞,等.超临界及超超临界循环流化床锅炉技术研究与应用[J].中国电机工程学报,2018,38(2):338-347.
[15]张维,高明明.掺烧煤泥循环流化床机组经济性优化运行研究[J].中国电机工程学报,2018,38(16):4807-4814.
[16]金森旺,高洪培,孙献斌,等.超临界600MW循环流化床锅炉燃用不同煤种燃烧特性及排放特性试验[J].热力发电,2017,46(4):46-51.
[17]李皓宇,朱宪然,刘彦鹏,等.600MW机组锅炉深度掺烧劣质煤技术[J].热力发电,2018,47(7):99-104.
[18]李永生,徐星,孙俊威.超超临界二次再热机组性能试验及分析[J].电力科技与环保,2017,33(6):40-43.
[2]冯俊凯,岳光溪,吕俊复.循环流化床燃烧锅炉[M].北京:中国电力出版社,2003.
[3]王志轩,潘荔,刘志强,等.中国煤电清洁发展现状及展望[J].电力科技与环保,2018,34(1):1-8.
[4]王宏伟.煤质对电厂锅炉运行和经济性影响的探究[J].经营管理者,2015(21):203.
[5]郝宏生.煤种变化对燃煤电厂综合经济性影响分析[J].锅炉技术,2018,49(2):8-11.
[6]赵航.煤质变化对燃煤发电机组运行热经济性影响研究[D].北京:华北电力大学,2017.
[7]黄海鹏.循环流化床锅炉非设计燃料掺烧优化[D].广州:华南理工大学,2016.
[8]樊泉桂.锅炉原理(第二版)[M].北京:中国电力出版社,2014.
[9]杨青森.煤矸石资源化利用现状及问题分析[J].科学技术创新,2018(10):25-26.
[10]邬万竹,王虎,顾从阳.煤泥及矸石等低热值煤循环流化床清洁高效利用关键技术研究[J].煤炭工程,2017,49(S1):41-45.
[11]叶恩清,张定海,何维,等.燃煤变化后发热量的计算及对锅炉效率修正[J].电站系统工程,2018(2):11-13.
[12]李军烁.应用偏增量法对燃煤锅炉热效率和供电煤耗的优化分析[J].锅炉技术,2018,49(4):36-41.
[13]马栋梁,闫顺林,李永华,等.煤质变化对排烟热损失影响的计算与分析[J].锅炉技术,2008,39(1):47-50.
[14]宋畅,吕俊复,杨海瑞,等.超临界及超超临界循环流化床锅炉技术研究与应用[J].中国电机工程学报,2018,38(2):338-347.
[15]张维,高明明.掺烧煤泥循环流化床机组经济性优化运行研究[J].中国电机工程学报,2018,38(16):4807-4814.
[16]金森旺,高洪培,孙献斌,等.超临界600MW循环流化床锅炉燃用不同煤种燃烧特性及排放特性试验[J].热力发电,2017,46(4):46-51.
[17]李皓宇,朱宪然,刘彦鹏,等.600MW机组锅炉深度掺烧劣质煤技术[J].热力发电,2018,47(7):99-104.
[18]李永生,徐星,孙俊威.超超临界二次再热机组性能试验及分析[J].电力科技与环保,2017,33(6):40-43.